A method for treating a mining subsidence area based on fly ash soil coating technology

Abstract

The present application relates to the technical field of wireless communication device, and discloses a kind of mining subsidence area treatment method based on fly ash coating soil technology, the device includes the drilling support of agricultural tractor, drilling and filler integration operation are realized by gear box, lifting screw rod drive auger rod, equipped with electromagnetic opening and closing nut, torque sensor and one-way coupling and other components, ensure segmented filling and well wall stability.Treatment method includes early reconnaissance matching parameter, after drilling operation, in turn deep filling pretreatment coal gangue, fly ash barrier layer, then backfilling raw soil and mature soil, finally raise ground surface and cover mature soil.By segmented filling, improve the density, fly ash layer blocks pollution, in situ use mature soil to restore arable layer, realize the rapid recovery of agricultural function in subsidence area, reduce the influence of harmful filler, improve the treatment efficiency and stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mining subsidence area treatment, and particularly relates to a mining subsidence area treatment method based on fly ash overburden soil technology. BACKGROUND

[0002] Ecological restoration and coal gangue resource utilization of mining subsidence area are important research directions in the field of mine environment treatment, and surface subsidence caused by mining of mineral resources not only causes landform fragmentation and soil structure damage, but also leads to vegetation degradation, which seriously affects the sustainable use of regional land resources. Traditional treatment methods usually use coal gangue backfilling in subsidence areas, but the existing technology has obvious environmental risks and technical defects.

[0003] At present, coal gangue subsidence area treatment mainly adopts surface stacking and mixed soil covering. This technical scheme has two key defects: first, the filling depth is relatively shallow, usually not more than 2 meters, which leads to too close distance between the gangue layer and the plough layer; second, there is a lack of effective pollution blocking measures, and sulfides in coal gangue will generate sulfuric acid and other acidic substances under the action of rainwater leaching and microorganisms. These acidic substances will form acid halo, which will significantly reduce the pH value of the surrounding soil and seriously affect crop growth. More seriously, the surface filling method used in the existing technology is difficult to realize precise layered filling, which cannot guarantee the filling density and cannot establish an effective pollution blocking layer. In addition, the traditional manual filling method is low in efficiency and difficult to control the filling quality, which is easy to cause well wall collapse and uneven filling. SUMMARY

[0004] The technical problem to be solved by the present application is that the traditional subsidence area backfilling scheme in the prior art has the defects of shallow filling depth of coal gangue and large damage to the original soil layer distribution, and therefore the present application provides a mining subsidence area treatment device based on fly ash overburden soil technology.

[0005] In order to achieve the above object, the technical scheme adopted by the present application is as follows: A mining subsidence area treatment device based on fly ash coating soil technology, characterized by comprising: a drilling support, the drilling support is installed on an agricultural tractor, a first gear box is fixedly connected to the bottom of the drilling support, the input end of the first gear box is in transmission connection with the power output end of the agricultural tractor, the output end of the first gear box is fixedly connected with a lifting lead screw, the lifting lead screw is drivingly connected to the drilling support through a bearing, a lifting sliding block is slidingly connected to the drilling support, an opening and closing nut is fixedly connected to the lifting sliding block, the lifting lead screw and the opening and closing nut are in meshing connection through threads, one end of the lifting sliding block is rotatably connected with a first driven pulley, the first driven pulley is slidingly connected with the lifting lead screw, the other end of the lifting sliding block is rotatably connected with a second driven pulley, the first driven pulley and the second driven pulley are in transmission connection through a belt, the second driven pulley is fixedly connected with a spiral drill rod, a filler through hole is formed in the spiral drill rod, and a flexible spiral conveying pipe is connected to the top of the spiral drill rod.

[0006] Further, the drilling support is rotatably connected with the agricultural tractor through a rotating shaft, a hydraulic cylinder is also rotatably connected to the agricultural tractor, and the other end of the hydraulic cylinder is rotatably connected to the drilling support, so that the hydraulic cylinder is used to drive the drilling support to stand up and fall down.

[0007] Further, a sliding groove is formed in the lifting lead screw, a sliding clamping block is fixedly connected to the first driven pulley, and the sliding clamping block is in sliding connection with the sliding groove, so that when the lifting lead screw rotates, the first driven pulley can not only move up and down with the lifting sliding block, but also rotate synchronously with the lifting lead screw.

[0008] Further, the opening and closing nut is an electromagnetic opening and closing nut, the opening and closing nut is driven to mesh with or disengage from the lifting lead screw by using electromagnetic force, a torque sensor is arranged on the flexible spiral conveying pipe, the opening and closing nut disengages from the lifting lead screw when the spiral conveying pipe normally conveys the filler, at this time, the spiral drill rod does not rise, when the torque sensor detects that the conveying of the spiral conveying pipe is blocked, it means that the drill hole at the bottom of the spiral drill rod is filled with the filler, at this time, the opening and closing nut will mesh with the lifting lead screw under the electromagnetic driving, so as to drive the spiral drill rod to rise, so as to further fill, which makes the filling more compact, and the drilling well wall is not easy to collapse and block, and the filler is easy to enter.

[0009] Further, a drilling sleeve is fixedly connected to the drilling support, the drilling sleeve is arranged outside the spiral drill rod, and a soil scattering disc is arranged on the upper portion of the drilling sleeve, which is used to scatter the soil drilled up to one side, so as to avoid the accumulation of the soil to affect the drilling.

[0010] Further, the bottom of the spiral drill rod is rotatably connected with six groups of drill rod movable plates through hinges, the drill rod movable plates are arranged in a triangular shape, and the six groups of drill rod movable plates are in the shape of a six-sided pyramid when they are closed, which is used to prevent the soil from entering the filler through hole when drilling.

[0011] Furthermore, a second gearbox is fixedly connected to the top of the drilling support, the lifting screw is fixedly connected to the input end of the second gearbox, a screw conveyor is installed inside the flexible screw conveying pipe, and the output end of the second gearbox is fixedly connected to the screw conveyor.

[0012] Furthermore, a one-way coupling is provided between the output end of the second gearbox and the screw conveyor, so that the second gearbox can only drive the screw conveyor to rotate in the forward direction, but cannot drive the screw conveyor to rotate in the reverse direction.

[0013] Furthermore, a telescopic corrugated pipe is fixedly connected to one end of the spiral conveying pipe, and the other end of the telescopic corrugated pipe is rotatably connected to the spiral drill rod, which facilitates the raising and lowering of the spiral drill rod.

[0014] This invention provides another technical solution: a method for treating mining subsidence areas based on fly ash-covered soil technology, comprising the following steps:

[0015] S1. Preliminary Investigation and Parameter Matching: First, a combination of 3D laser scanning and geological drilling was used to determine the extent, depth, soil stratification, and groundwater depth of the subsidence area. Soil samples were collected simultaneously to test pH, organic matter content, and heavy metal concentration. Based on the subsidence depth, the drilling depth and layer filling thickness were set to ensure that the surface elevation after filling was level with the surrounding area.

[0016] S2. Drilling operation: Adjust the verticality of the drilling equipment according to the terrain of the subsidence area, connect and debug the power system to ensure the coordinated operation of drilling, transportation and filling links, meet the requirements of layered soil extraction and precise filling, and then start the drilling equipment to drill. The soil is dispersed to the designated area through auxiliary devices. After drilling to the design depth, stop and keep the support structure in the drilling channel stable to prevent the well wall from collapsing.

[0017] S3. Deep filling of coal gangue: The pre-treated coal gangue is transported to the bottom of the well through the drilling channel via the conveying system. At this time, the support structure in the drilling channel is kept in place to ensure the stability of the well wall. When the conveying is obstructed, it is determined that the space at the bottom of the well is filled. The support structure is driven to rise 0.5-1.0m and then stopped. The filling continues. This process is repeated until the coal gangue is filled to the preset depth from the bottom of the well.

[0018] S4. Fly ash barrier layer filling: After the coal gangue filling is completed, switch the conveying system to fly ash and fill according to the above process. The thickness is controlled at 0.8-1.2m to form a pollution barrier.

[0019] S5. Deep subsoil backfilling: The deep subsoil excavated above the fly ash layer is backfilled using a method of simultaneous conveying and compaction by rotation and vibration, up to 0.5m from the wellhead, to reserve space for the subsequent surface mature soil transition layer and ground elevation.

[0020] S6. Deep layer of raw soil backfill: The 0.5m surface layer of mature soil is accurately filled on the deep layer of raw soil, and the well mouth is flush, light compaction process is adopted, which avoids the direct mixing of raw soil and the upper layer of raised mature soil, and provides initial growth medium for plant root system, and enhances the continuity of soil layer;

[0021] S6. Surface lifting and mature soil covering operation: The surface layer of mature soil drilled out is screened on site, 5%-10% of decomposed organic fertilizer is mixed if the fertility is insufficient, the organic matter content is ensured to reach the standard, the surface layer of mature soil is continued to be used for ground lifting in the subsidence area near the well mouth, is layered and spread and is light compacted, and finally the ground elevation is leveled with the surrounding non-subsidence area, the slope is ≤3°, and the total thickness of the surface layer of mature soil is dynamically adjusted according to the subsidence depth, and the total thickness of the tillage layer is ensured to be ≥0.8m.

[0022] Technical effects and advantages of the present application:

[0023] The mining subsidence area treatment method based on the fly ash covering layer soil technology changes the surface layer stacking and mixed soil covering mode of the traditional subsidence area backfill, adopts local tunneling, and adopts the mode of coal gangue deep filling, fly ash covering and raw soil covering, replaces the soil that can be used for cultivation in situ, and performs ground leveling, the mode is small in damage to the original soil layer, fast in recovery, and is beneficial to the rapid recovery of the function of agricultural planting. BRIEF DESCRIPTION OF DRAWINGS

[0024] The disclosure of the present application will be explained with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present application. In the drawings, the same reference numerals are used to refer to the same parts:

[0025] Figure 1 It is a front view structural schematic diagram of the present application;

[0026] Figure 2 It is a hydraulic cylinder installation structural schematic diagram of the present application;

[0027] Figure 3 It is a spiral drill pipe and drill sleeve structure schematic diagram of the present application;

[0028] Figure 4 It is a lifting screw structure schematic diagram of the present application;

[0029] Figure 5 It is a Figure 4 It is an enlarged structural schematic diagram of A in the present application;

[0030] Figure 6 It is a Figure 1 It is an enlarged sectional view structural schematic diagram of B in the present application;

[0031] Figure 7 It is a drill pipe movable plate closing structure schematic diagram of the present application;

[0032] Figure 8 Figure 1 is a schematic diagram of the opening structure of the drill rod movable plate according to the present application.

[0033] Legend: 1, drilling support; 2, agricultural tractor; 3, hydraulic cylinder; 4, first gear box; 5, lifting screw rod; 501, sliding groove; 6, lifting sliding block; 7, opening and closing nut; 8, first follow-up pulley; 801, sliding clamping block; 9, second follow-up pulley; 10, spiral drill rod; 1001, filler through hole; 11, drilling sleeve; 1101, soil disc; 12, drill rod movable plate; 13, second gear box; 14, flexible spiral conveying pipe; 15, spiral conveyor; 16, telescopic corrugated pipe. DETAILED DESCRIPTION

[0034] The technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0035] Please refer to Figures 1-8The utility model provides a kind of mining subsidence area treatment device based on fly ash coating soil technology, including drilling support 1, drilling support 1 is installed on agricultural tractor 2, the movement of device is realized by means of agricultural tractor 2, improve the flexibility and operating range of device. First gear box 4 is fixedly connected at the bottom of drilling support 1, the input end of first gear box 4 is transmissionally connected with the power output end of agricultural tractor 2, can distribute transmission the power of agricultural tractor 2, the output end of first gear box 4 is fixedly connected with lifting lead screw 5, lifting lead screw 5 is actively connected on drilling support 1 by bearing, so that lifting lead screw 5 can stably rotate. Lifting slider 6 is slidably connected on drilling support 1, opening and closing nut 7 is fixedly connected on lifting slider 6, lifting lead screw 5 and opening and closing nut 7 are mutually engaged by thread, when lifting lead screw 5 rotates, opening and closing nut 7 is driven to slide up and down along drilling support 1 by thread transmission. Lifting slider 6 one end is rotatably connected with first follow-up pulley 8, first follow-up pulley 8 is slidably connected with lifting lead screw 5, lifting slider 6 other end is rotatably connected with second follow-up pulley 9, first follow-up pulley 8 and second follow-up pulley 9 are transmissionally connected by belt, realize the transmission of power, second follow-up pulley 9 is fixedly connected with auger rod 10, auger rod 10 rotates and carries out well drilling operation under the driving of second follow-up pulley 9. Filling material through hole 1001 is arranged in auger rod 10, for conveying filling material, flexible auger pipe 14 is connected to the top of auger rod 10, to facilitate the conveying of filling material to filling material through hole 1001. The structure realizes the integrated operation of well drilling and filling by providing power by agricultural tractor, improves the treatment efficiency.

[0036] Drilling support 1 is rotatably connected with agricultural tractor 2 by rotating shaft, so that drilling support 1 can rotate around rotating shaft, hydraulic cylinder 3 is also rotatably connected on agricultural tractor 2, the other end of hydraulic cylinder 3 is rotatably connected on drilling support 1, and hydraulic cylinder 3 is used to drive the erection and laying of drilling support 1. In the device transportation state, the hydraulic cylinder 3 is retracted, the drilling support 1 is laid down, the occupied space of the device is reduced, and the transportation is facilitated. In the operation state, the hydraulic cylinder 3 is elongated, the drilling support 1 is pushed to rotate around the rotating shaft to the vertical state, the erection of the drilling support is realized, and stable support is provided for the well drilling operation. The design makes the device conversion and operation conversion more convenient and efficient.

[0037] The lifting screw 5 is provided with a sliding groove 501, and the first follower pulley 8 is fixedly connected with a sliding block 801 which is in sliding connection with the sliding groove 501. In implementation, when the lifting screw 5 rotates, the lifting block 6 is driven to move up and down through thread transmission, at this time, the first follower pulley 8 moves up and down synchronously with the lifting block 6, and the sliding block 801 slides in the sliding groove 501, and at the same time, the first follower pulley 8 rotates synchronously with the lifting screw 5 due to the clamping effect of the sliding block 801 and the sliding groove 501, and then drives the second follower pulley 9 and the auger rod 10 to rotate through the belt. This structure ensures that the auger rod 10 always rotates during the up and down movement, ensures the continuity of the drilling operation, and improves the drilling efficiency.

[0038] The opening and closing nut 7 is an electromagnetic opening and closing nut which is driven to engage with and disengage from the lifting screw 5 by electromagnetic force, and the flexible auger pipe 14 is provided with a torque sensor which monitors the torque change of the auger pipe in real time. When the auger pipe 14 normally conveys the filler, the torque is in a normal range, the electromagnetic opening and closing nut is powered off, and is disengaged from the lifting screw 5 under the action of the spring force, at this time, the rotation of the lifting screw 5 will not drive the lifting block 6 to move, and the auger rod 10 will not rise, thereby maintaining the support to the well wall and preventing the well wall from collapsing. When the auger pipe 14 is blocked and the torque suddenly increases, it means that the drill hole at the bottom of the auger rod 10 is filled with the filler, at this time, the torque sensor sends a signal to the control system, the control system makes the electromagnetic opening and closing nut be powered on, generates electromagnetic force to overcome the spring force and engage with the lifting screw 5, the lifting screw 5 rotates to drive the lifting block 6 to drive the auger rod 10 to rise, so as to further fill. When the auger rod 10 rises, the filler channel is unblocked, the torque returns to normal, the torque sensor sends a signal again, the electromagnetic opening and closing nut is powered off and disengaged, and the auger rod 10 stops rising. Such a cycle process makes the filling more compact, and avoids the problem of the well wall collapsing and blocking after the auger rod 10 is lifted, thereby ensuring that the filler enters smoothly.

[0039] The drilling support 1 is fixedly connected with a drilling sleeve 11 which is sleeved outside the auger rod 10 to guide and stabilize the auger rod 10 and prevent the auger rod 10 from deviating during drilling. The upper part of the drilling sleeve 11 is provided with a soil scattering disc 1101 which is trumpet-shaped and whose edge is inclined downward. In implementation, the soil drilled up by the auger rod 10 rises to the upper part of the drilling sleeve 11 along the auger blade, falls on the soil scattering disc 1101, and is scattered to one side along the edge of the soil scattering disc 1101 under the action of gravity, thereby avoiding the soil from being accumulated at the drilling hole to affect the drilling operation and ensuring the smoothness of the drilling process.

[0040] The bottom of the auger drill rod 10 is connected with the drill rod movable plate 12 through a hinge rotation, the drill rod movable plate 12 is provided with six groups, and the drill rod movable plate 12 is in a triangular shape. In the drilling process, the auger drill rod 10 drills downward, the soil produces pressure on the drill rod movable plate 12, the six groups of drill rod movable plates 12 are closed to be in a hexagonal pyramid shape, the soil is effectively prevented from entering the filler through hole 1001, and the filler through hole 1001 is ensured to be unobstructed. When the filler operation is performed, the filler is conveyed downward from the filler through hole 1001, a thrust is generated on the drill rod movable plate 12, the movable plate is opened by overcoming the soil pressure, and the filler smoothly enters the well bottom. The structure realizes the double functions of preventing blockage during drilling and unobstructed during filling, and improves the reliability of the device. The top of the drilling support 1 is fixedly connected with the second gear box 13, the lifting lead screw 5 is fixedly connected with the input end of the second gear box 13, the flexible auger conveying pipe 14 is provided with the auger conveyor 15, and the output end of the second gear box 13 is fixedly connected with the auger conveyor 15. In implementation, the lifting lead screw 5 rotates to drive the input end of the second gear box 13 to rotate, the power is transmitted to the auger conveyor 15 through the speed change and direction change of the second gear box 13, the auger conveyor 15 is driven to rotate, and the conveying of the filler such as coal gangue and fly ash is realized. The structure utilizes the same power source to drive the auger drill rod 10 and the auger conveyor 15, simplifies the power system of the device, and reduces energy consumption and cost.

[0041] A one-way coupling is arranged between the output end of the second gear box 13 and the auger conveyor 15, the one-way coupling only allows the power to be transmitted from the output end of the second gear box 13 to the auger conveyor 15, and when the auger conveyor 15 is subjected to a reverse force, the one-way coupling slips to cut off the reverse power transmission. In the working of the device, it is ensured that the second gear box 13 can only drive the auger conveyor 15 to rotate forward for filler conveying, and when the auger drill rod 10 rises or other conditions may cause the auger conveyor 15 to have a reverse rotation trend, the one-way coupling prevents the reverse rotation, avoids the backflow of the filler, and ensures the stability and continuity of the filler conveying. One end of the auger conveying pipe 14 is fixedly connected with the telescopic bellows 16, one end of the telescopic bellows 16 is rotationally connected with the auger drill rod 10. In the lifting process of the auger drill rod 10, the telescopic bellows 16 can deform by stretching and contracting with the movement of the auger drill rod 10, compensate for the length change caused by the upward and downward movement of the auger drill rod 10, and the rotationally connected mode ensures that the auger conveying pipe 14 does not rotate with the auger drill rod 10 when the auger drill rod 10 rotates. The structure ensures the unobstructed and stable connection of the filler conveying channel in the lifting process of the auger drill rod 10, and improves the reliability of the device working.

[0042] Specifically, in the embodiment, the device can be installed at the rear of a standard agricultural tractor, connected through a three-point suspension mechanism, and suitable for coal gangue filling operation in various mining subsidence areas.

[0043] The power transmission system specifically includes:

[0044] 1. The tractor power output shaft outputs power at a standard speed of 540 rpm;

[0045] 2. The first gear box 4 uses helical gear transmission with a speed ratio of 1:4, reducing the speed to 135 rpm;

[0046] 3. The lifting screw 5 is made of 40Cr alloy steel, with a diameter of 40 mm and a lead of 50 mm. The surface is treated with high-frequency quenching, with a hardness of HRC55-60;

[0047] 4. The electromagnetic opening and closing nut 7 is designed with trapezoidal threads, with a thread tolerance grade of 7H / 7g, an axial load capacity of 16 kN, and a power-on closing response time of ≤0.1 seconds.

[0048] Please refer to Figure 7 and Figure 8 . The auger rod 10 is made of 45 steel with quenching and tempering treatment, with an outer diameter of 200 mm, an inner hole diameter of 120 mm, and a length of 4.5 meters. The auger rod surface spiral blade height is 50 mm, the pitch is 300 mm, and the blade edge is embedded with hard alloy wear-resistant strip. The movable plate 12 of the auger rod is composed of 6 Mn13 wear-resistant steel plates with a thickness of 20 mm, each in the shape of an equilateral triangle with a side length of 150 mm. The movable plate is connected to the bottom end of the auger rod through a hinge mechanism, forming a six-sided pyramid structure with a cone angle of 60° when closed, with a cooperation gap between the auger rod cylinder and the movable plate controlled within the range of 0.3-0.5 mm. The opening and closing angle of the movable plate can be adjusted within the range of 0-120° through the hydraulic system.

[0049] The drilling sleeve 11 adopts a double-layer structure design: the inner cylinder diameter is 210 mm, the wall thickness is 8 mm; the outer cylinder diameter is 300 mm, the wall thickness is 6 mm; the two layers are filled with polyurethane buffer material; the top soil dispersing disc 1101 is precisely set at an angle of 45°, which can uniformly disperse the drilled soil within a radius of 5 meters.

[0050] The flexible auger conveying pipe 14 has an inner diameter of 150 mm and is made of wear-resistant rubber and steel wire braid composite, with a bending radius not less than 800 mm. The auger 15 has a shaft diameter of 50 mm and a pitch of 200 mm, and the rotational speed is controlled within the range of 30-90 rpm by the second gear box 13.

[0051] The one-way coupling uses a freewheel structure to ensure that the auger 15 can only rotate in one direction, preventing material backflow. The torque sensor is integrated at the proximal end of the conveying pipe, with a measurement range of 0-500 N·m and a measurement accuracy of ±1% FS.

[0052] The control system core uses an industrial-grade PLC controller, which mainly realizes the following functions:

[0053] 1. Real-time acquisition of torque sensor data with a sampling frequency of 100 Hz;

[0054] 2. When the delivery resistance is detected to exceed 300 N·m, the following control sequence is triggered immediately:

[0055] The electromagnetic opening and closing nut 7 is energized to close, with a delay of <50 ms;

[0056] The lifting motor is started to drive the drill pipe to rise at a speed of 50 mm / min;

[0057] The rising distance reaches 0.8 m and stops automatically;

[0058] 3. Display key parameters through HMI human-machine interface:

[0059] Current drilling depth, accuracy ±10 mm;

[0060] Filler material cumulative amount, accuracy ±5 kg;

[0061] System pressure state.

[0062] A mining subsidence area treatment method based on fly ash coating soil technology, comprising the following steps:

[0063] S1. Preliminary survey and parameter matching: first, use the combination of three-dimensional laser scanning and geological drilling to determine the range, depth, soil layering structure and groundwater depth of the subsidence area. In specific implementation, the three-dimensional laser scanning uses a scanning frequency of not less than 50 points / ㎡ of point cloud density to obtain high-precision topographic data of the subsidence area; the geological drilling arranges drill holes according to a 50m×50m grid, with a depth to the bedrock surface, and collects rock core samples of each soil layer. Soil samples are collected simultaneously to detect pH value, organic matter content and heavy metal concentration. According to the subsidence depth, set the drilling depth and layering filling thickness, such as when the subsidence depth is 3-5m, the drilling depth is 1m above the bedrock, the coal gangue filling thickness accounts for 60%, the fly ash barrier layer accounts for 15%, and the raw soil and mature soil accounts for 25%, to ensure that the filling surface elevation is level with the surrounding area. Effect principle: through accurate survey, achieve parameter customization, avoid underfilling or overfilling, and provide scientific basis for subsequent layering treatment.

[0064] S2. Drilling operation: Adjust the verticality of the drilling device according to the terrain of the subsidence area, use the inclination sensor for real-time monitoring, and fine-tune the angle of the drilling support 1 through the hydraulic cylinder 3 to ensure that the verticality deviation is ≤0.5°. Connect the power output end of the agricultural tractor 2 with the first gear box 4, and run the device for 5 minutes in the debugging state to check the rotation speed of the auger rod 10, the running stability of the lifting slider 6, and the sealing performance of the flexible spiral conveying pipe 14. After starting the drilling device, the auger rod 10 rotates clockwise to drill, and the drilled soil rises along the spiral blade to the soil distribution disc 1101 and is distributed to the temporary soil storage area 3-5 meters away from the wellhead. After drilling to the designed depth, keep the drilling sleeve 11 in place to support the auger rod 10. Effect principle: Verticality control ensures that the drilling channel is vertical, avoiding filling deviation; dispersed soil facilitates subsequent classification and backfilling, and in-situ support prevents well wall collapse using the rigid structure of the drilling sleeve 11.

[0065] S3. Coal gangue deep filling: Pre-treated coal gangue is transported through the flexible spiral conveying pipe 14, and the rotation speed of the spiral conveyor 15 is set to 40-60r / min. At this time, the electromagnetic opening and closing nut 7 is in a disengaged state, and the auger rod 10 is stationary to support the well wall. When the torque sensor detects that the conveying torque exceeds the set threshold, it is determined that the well bottom is filled, and the control system drives the electromagnetic opening and closing nut 7 to engage, and the lifting screw 5 drives the auger rod 10 to rise 0.5-1.0m and then resets to disengage, and continues to fill. Repeat the operation until the coal gangue is filled to the pre-set depth from the well bottom. Effect principle: Subsection filling utilizes the space formed by the upward movement of the auger rod 10 to realize layer-by-layer compaction, with a density of 1.6-1.8g / cm 3 , which is 20%-30% higher than traditional one-time filling, enhancing the stability of the foundation.

[0066] S4. Fly ash barrier layer filling: Switch the conveying system to fly ash and fill according to the S3 process, with a thickness control of 0.8-1.2m. The rotation speed of the spiral conveyor 15 is reduced to 30r / min during filling to ensure uniform distribution of fly ash. Effect principle: Fly ash hydration reaction forms a dense calcium silicate gel, with a permeability coefficient ≤1×10 -7 cm / s, effectively blocking the upward migration of harmful substances in coal gangue, and the pH value is stable at 8-9, which can passivate heavy metal ions.

[0067] S5. Deep layer of raw soil backfilling: The deep layer of raw soil drilled out is backfilled through the conveying system, and the auger rod 10 is started in low speed reverse rotation to generate vibration compaction effect, and backfilled to 0.5m away from the wellhead. Effect principle: Rotational vibration causes raw soil particles to rearrange, with a dry density of 1.4-1.5g / cm 3 , reducing post-settlement and providing a buffer for the surface layer of mature soil transition layer.

[0068] S6. Surface mature soil filling: Fill 0.5m of surface mature soil on top of deep raw soil, use light vibration compaction, and make it level with the wellhead. Effect principle: Light compaction avoids destroying the mature soil aggregate structure, and the porosity is maintained at 40%-45%, providing a breathable growth environment for plant roots, while isolating raw soil and raising the soil layer.

[0069] S7. Surface raising and mature soil covering operation: Vibrate and sieve the surface mature soil in the temporary soil pile area, detect the organic matter content, and if it is less than 1.5%, mix in 5%-10% of decomposed organic fertilizer. Layered spreading of mature soil on the surface of the subsidence area, each layer thickness 20-30cm, use track-type light roller compactor to compact, compactness control at 85%-90%. The final ground elevation is level with the surrounding area, with a slope of ≤3°, and the total thickness of the tillage layer is ≥0.8m. Effect principle: In-situ use of mature soil reduces the cost of taking soil from elsewhere, organic fertilizer improves and enhances soil fertility, slope control prevents soil erosion, and meets the needs of crop cultivation;

[0070] The following is an example of the treatment process of a standard subsidence pit to illustrate the specific implementation process of the embodiment:

[0071] S1. Geological survey and parameter setting: RIEGL VZ-400 three-dimensional laser scanner is used to measure the depth of the subsidence area as 4.2m; soil detection shows pH=4.8, sulfide content 1.2%; set the drilling depth to 4.5m, coal gangue filling layer thickness to 3.0m, and fly ash barrier layer thickness to 1.0m;

[0072] S2. Automatic drilling stage:

[0073] The hydraulic cylinder 3 lifts the support to the vertical position; the drill rod drills at a rate of 0.6m / min, and the soil disc uniformly discharges the drill cuttings; it automatically stops when the design depth of 4.5m is reached;

[0074] S3. Blocked feedback filling stage: coal gangue is injected through the screw conveyor at a speed of 60rpm; the system records 5 times of resistance overrun events, corresponding to 5 times of drill rod lifting; the cumulative filling height reaches 3.02m;

[0075] S4. Barrier layer laying stage: switch the hopper to deliver fly ash; continuously fill to a thickness of 1.05m;

[0076] S5. Raw soil backfilling stage: deep raw soil falls at a speed of 30rpm; start the vibrator synchronously; compact to 0.5m from the wellhead;

[0077] S6. Surface repair stage: sieve the mature soil through a 10 mesh sieve, mix in 8% of organic fertilizer; light compaction to the ground level.

[0078] The above merely provides an example of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A mining subsidence area remediation device based on fly ash-covered soil technology, characterized in that, include: A drilling support is mounted on an agricultural tractor. A first gearbox is fixedly connected to the bottom of the drilling support. The input end of the first gearbox is connected to the power output end of the agricultural tractor. A lifting screw is fixedly connected to the output end of the first gearbox. The lifting screw is actively connected to the drilling support via a bearing. A lifting slider is slidably connected to the drilling support. A locking nut is fixedly connected to the lifting slider. The lifting screw and the locking nut are threaded together. A first follower pulley is rotatably connected to one end of the lifting slider. The first follower pulley is slidably connected to the lifting screw. A second follower pulley is rotatably connected to the other end of the lifting slider. The first and second follower pulleys are connected via a belt drive. A spiral drill rod is fixedly connected to the second follower pulley. A packing through hole is opened inside the spiral drill rod. A flexible spiral conveying pipe is connected to the top of the spiral drill rod. The lifting screw has a sliding groove, and the first follower pulley is fixedly connected to a sliding block, which is slidably connected to the sliding groove.

2. The mining subsidence area treatment device based on fly ash covering soil technology according to claim 1, characterized in that, The drilling support is rotatably connected to the agricultural tractor via a rotating shaft. A hydraulic cylinder is also rotatably connected to the agricultural tractor, and the other end of the hydraulic cylinder is rotatably connected to the drilling support.

3. The mining subsidence area treatment device based on fly ash covering soil technology according to claim 1, characterized in that, The opening and closing nut is an electromagnetic opening and closing nut, which uses electromagnetic force to drive the opening and closing nut to engage and disengage with the lifting screw. At the same time, a torque sensor is installed on the flexible spiral conveying tube.

4. The mining subsidence area treatment device based on fly ash covering soil technology according to claim 1, characterized in that, A drilling sleeve is fixedly connected to the drilling support. The drilling sleeve is sleeved on the outside of the auger drill pipe, and a soil distribution plate is provided on the upper part of the drilling sleeve.

5. A mining subsidence area treatment device based on fly ash covering soil technology according to claim 1, characterized in that, The bottom of the auger drill rod is rotatably connected to a drill rod movable plate via a hinge. There are six sets of drill rod movable plates, and the drill rod movable plates are triangular in shape. When the six sets of drill rod movable plates are closed, they form a hexagonal pyramid shape.

6. The mining subsidence area treatment device based on fly ash covering soil technology according to claim 1, characterized in that, The top of the drilling support is fixedly connected to a second gearbox, the lifting screw is fixedly connected to the input end of the second gearbox, a screw conveyor is installed inside the flexible screw conveying pipe, and the output end of the second gearbox is fixedly connected to the screw conveyor.

7. A mining subsidence area treatment device based on fly ash covering soil technology according to claim 6, characterized in that, A one-way coupling is provided between the output end of the second gearbox and the screw conveyor.

8. A mining subsidence area treatment device based on fly ash covering soil technology according to claim 1, characterized in that, One end of the spiral conveying pipe is fixedly connected to a telescopic corrugated pipe, and one end of the telescopic corrugated pipe is rotatably connected to the spiral drill rod.

9. A method for treating mining subsidence areas using a device based on fly ash-covered soil technology as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Preliminary investigation and parameter matching: First, a combination of three-dimensional laser scanning and geological drilling was used to clarify the scope, depth, soil layer structure and groundwater depth of the subsidence area. Soil samples were collected simultaneously to test pH value, organic matter content and heavy metal concentration. The drilling depth and layer filling thickness were set according to the subsidence depth to ensure that the surface elevation after filling is the same as the surrounding area. S2. Drilling operation: Adjust the verticality of the drilling equipment according to the terrain of the subsidence area, connect and debug the power system to ensure the coordinated operation of drilling, transportation and filling links, meet the requirements of layered soil extraction and precise filling, and then start the drilling equipment to drill. The soil is dispersed to the designated area through auxiliary devices. After drilling to the design depth, stop and keep the support structure in the drilling channel stable to prevent the well wall from collapsing. S3. Deep filling of coal gangue: The pre-treated coal gangue is transported to the bottom of the well through the drilling channel via the conveying system. At this time, the support structure in the drilling channel is kept in place to ensure the stability of the well wall. When the conveying is obstructed, it is determined that the space at the bottom of the well is filled. The support structure is driven to rise 0.5-1.0m and then stopped. The filling continues. This process is repeated until the coal gangue is filled to the preset depth from the bottom of the well. S4. Fly ash barrier layer filling: After the coal gangue filling is completed, switch the conveying system to fly ash and fill according to the above process. The thickness is controlled at 0.8-1.2m to form a pollution barrier. S5. Deep subsoil backfilling: The deep subsoil excavated above the fly ash layer is backfilled using a method of simultaneous conveying and compaction by rotation and vibration, up to 0.5m from the wellhead, to reserve space for the subsequent surface mature soil transition layer and ground elevation. S6. Deep subsoil backfill: 0.5m of topsoil is precisely filled on top of the deep subsoil, level with the wellhead, and a light compaction process is adopted to avoid direct mixing of subsoil and topsoil, while providing a preliminary growth medium for plant roots and enhancing soil coherence. S6. Surface elevation and topsoil covering: The drilled topsoil is screened on-site. If the fertility is insufficient, 5%-10% well-rotted organic fertilizer is added to ensure that the organic matter content meets the standard. In the subsidence area near the wellhead, the topsoil is used to raise the ground. It is spread in layers and lightly compacted to make the surface elevation level with the surrounding non-subsidence area, with a slope ≤3°. The total thickness of the topsoil is dynamically adjusted according to the subsidence depth to ensure that the total thickness of the cultivated layer is ≥0.8m.

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